吸收衰减
参考答案：
指声能在传播过程中，因小界面的散射，大界面的反射，声束的扩散以及软组织对超声能量的吸收等而使声能逐渐减弱。
This famous article written by Henry is well worth , but I think it is not worthy at all.
A．reading; to be translated
B．reading; translating
C．being read; to be translated
D．to be read; of being translated
张某领取失业保险金的期限最长为：( )。
A．6个月
B．12个月
C．18个月
D．24个月
